Small cell osteosarcoma of mandible: a rare case report and review of literature.

Osteosarcoma is the most common primary malignant tumor of bone but only 5% of these tumours occur in the jaws. Of all the varieties of osteosarcoma, the juxtacortical type is rare and comprises only less than 4% of all osteosarcomas. Juxtacortical osteosarcoma is further subdivided into parosteal (low grade) and periosteal (high grade). Osteosarcomas can be categorized histologically mainly into chondroblastic, osteoblastic, fibroblastic and numerous others. One of the rare histological variant is small cell osteosarcoma which consists of sheets of round cells that produce an osteoid matrix. The aim of this article is to present a rare case of periosteal osteosarcoma of mandible which on histopathological examination showed characteristics of small cell tumour